Carried out by Marisa Montoya and Levermann from the Universidad Complutense de Madrid, Madrid, Spain, the study took into account the Atlantic meridional overturning circulation (AMOC) during the Last Glacial Maximum (LGM), which occurred roughly 21,000 years ago.

Though the AMOC regulates climate by distributing heat to the worlds oceans and involves deepwater formation in the North Atlantic, it is poorly constrained in model scenarios.

Towards this purpose, the researchers tried to characterize the AMOC during the LGM.

Noting that wind fields during the LGM are not well understood, Montoya and Levermann modeled how changes in wind strength would affect AMOC strength.

The model that emerged accurately simulated surface winds, which facilitate horizontal and vertical mixing in the ocean.

By assuming that LGM wind stresses are proportional to those experienced today, the authors of the study discovered that below certain thresholds of wind strength, North Atlantic deepwater formation takes place south of Greenland and the AMOC is relatively weak.

Above this threshold, deepwater formation occurs farther north, leading to a vigorous AMOC.